Gardenia leaves turning black
The editor answers everyone's questions about the knowledge of Gardenia in the flower clinic. The leaves of Gardenia turn black. Please see the detailed introduction below.
There are two possible reasons for the black leaves and powerless drooping of Gardenia leaves:
First, excessive watering: usually the plants are watered when the topsoil feels a little dry, preferably before 9 a.m. and between 5-7 p.m., and each time should be watered thoroughly. When the climate is relatively humid, the plant's evapotranspiration is slower, and watering twice a day can easily cause the roots to be unable to breathe normally and even rot. Since the roots in the pot are not easily visible, the aboveground parts such as leaves will show symptoms such as yellowing, drooping, defoliating, and withering. At this time, you can dig up the plant to see if the roots have rotted, cut off the black roots and plant them again, and water according to the above method.
Second, tea soot disease caused by pest infestation
There are three kinds of pests that can cause soot disease. If you can't tell them apart, please refer to books:
1. Aphids: usually light green, about 3mm, often found in soft parts of new buds and tender buds. pound two garlic bulbs into juice, add 1 liter of water, and then spray the affected plants.
2. Mealybugs: white, about 2-3mm, often found on the back of leaves. Mix 1g of laundry detergent with 120cc of water and a few drops of peanut oil or corn oil, stir well and spray, or use a brush soaked in water to remove.
3. Scale insects: various species, brown, white or light yellow, about 1.5-3mm,吸食茎、枝、叶的汁液, 成虫不会移动. Use a cotton swab dipped in alcohol or soapy water to remove.
If the above methods still do not work, you need to use insecticides.
Key points for managing Gardenia:
1. Cultivation venue: Gardenia prefers a warm and humid climate, with a suitable growth temperature of about 20℃, and should be selected in a semi-sunlit place, avoiding strong sunlight. It should be shaded at noon in summer and protected from the cold in winter.
2. Soil: likes deep, fertile, slightly acidic, fertilizer-retaining, and well-drained humus loam soil. Potted plants should be repotted every year, with organic fertilizers such as bone meal or active organic fertilizers placed at the bottom of the pot, covered with 8-10cm of soil, and then the plant is placed in it.
3. Fertilization: After planting, apply a slow-release fertilizer such as "Haokang No.1" every 3 months, and apply it away from the base.
4. Pruning: After 2 years of planting, prune dense branches, withered branches, diseased branches, sprawling branches, or branches too close to the ground every spring to facilitate air circulation and direct sunlight.
The above sharing of how to deal with the black leaves of Gardenia can help you. Don't forget to check out more flower cultivation experience and common sense!